Method for winding a strand of material around a substrate and products formed thereby

ABSTRACT

A process for applying a cushioning material around a substrate, that is a catalytic converter or a muffler, includes rotating the substrate, and winding a strand of fibers around an outer surface of the rotating substrate.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY

This invention relates to a process for winding a strand of material around a substrate and to the product formed using such process. In certain embodiments, a roving material is wound around a catalytic converter substrate or a muffler insert.

BACKGROUND OF THE INVENTION

Many types of catalytic converters include a mat or woven mesh material and a catalyst substrate which are then inserted into a suitable metal cannister. The catalyst substrate is often made of an easily crushable material, such as a honeycomb metal material or a ceramic material. In the past, it has been difficult to fasten the mat or woven mesh onto the catalyst substrate, and then insert the mat-enclosed substrate into the metal cannister, without damaging the catalyst substrate.

Also, many types of exhaust mufflers include a sound absorbing material surrounding a muffler, such as one or more pipes, which is then inserted into a suitable muffler shell. One common type of exhaust muffler is a clamshell muffler which is assembled by placing the muffler insert and the sound absorbing material within an opened muffler shell, and then joining an upper section of the shell to a lower section of the shell by welding or crimping. Another common muffler has an insert which is pushed into a cannister. Also, various mufflers and methods for making mufflers can include, for example, the following which have been invented by one or more of the inventors herein:

U.S. Pat. No. 6,412,596 B1 to Brandt et al. describes a process for filling a muffler shell with loose fibrous material.

U.S. Pat. No. 6,581,723 B2 to Brandt et al. describes a muffler shell filling process where fibrous material is fed into a muffler shell with a nozzle.

U.S. Pat. No. 6,607,052 B2 to Brandt et al. describes a muffler shell filling process and a muffler filled with a fibrous material where the muffler shell is filled with a bag of fibrous material.

U.S. Pat. No. 6,883,558 B2 to Jander describes a method of filling a muffler cavity with a fibrous material by inserting wetted fibrous material into a muffler chamber.

U.S. Pub. No. 2005/0001012 A1 to Brandt et al. describes a technique to fill mufflers by enclosing a muffler insert in a cavity, filling the cavity with loose fibrous material and wrapping a yarn thread around the loose fibrous material.

SUMMARY OF THE INVENTION

In one aspect, the invention relates to a process for applying a cushioning material around a substrate. The process includes rotating the substrate, and winding a cushioning material around an outer surface of the rotating substrate. In certain embodiments, the cushioning material is a bulked up roving material. In certain embodiments, the substrate is a catalytic converter substrate or a muffler insert.

In another aspect, the invention also relates to a process for winding a cushioning material around a substrate that has a longitudinal axis and opposing first and second ends. The first end of the substrate is positioned against a drive plate which is configured to rotate the substrate about the longitudinal axis. A press plate is positioned against the second end of the substrate and applies a pressure sufficient to substantially hold the substrate against the drive plate. The drive plate is rotated such that the substrate and press plate rotate about the longitudinal axis and the cushioning material is wound around the rotating substrate.

In certain embodiments, the drive plate and the press plate have a resilient engaging surface which substantially holds the substrate in position between the drive plate and the press plate.

In another aspect, the present invention relates to an insert for a catalytic converter which includes a catalytic converter substrate having a roving material wound around an outer surface of the catalytic converter substrate.

In yet another aspect, the present invention relates to an insert for a muffler which includes a muffler insert having a roving material wound around an outer surface of the muffler insert.

In still another aspect, the present invention relates to a method for forming a catalytic converter which includes: providing a catalytic converter substrate; winding a cushioning material around the catalytic converter substrate to form an insert; and, positioning the insert within a catalytic converter cannister.

Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified, partially diagrammatic illustration of a manufacturing process for winding a material around a substrate.

FIG. 2 is a schematic, perspective illustration, partially broken away, showing a catalytic converter having a catalytic converter substrate with a roving material wound around the catalytic converter substrate.

FIG. 3 is a schematic, perspective illustration, partially broken away, showing a muffler having a muffler insert with a roving material wound around the muffler insert.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS

The present invention provides apparatus 10 where a substrate 12 is wound with a cushioning material, such as a strand of cushioning material 14. For example, while not wishing to be held only to the following cross-sectional shapes, in certain embodiments, the substrate 12 can be a catalytic converter substrate which has a substantially circular cross-section, while in other embodiments, the substrate 12 can be a muffler insert which has any suitable cross-sectional shape, including, but not limited to elliptical, square, rectangular, trapezoidal, and the like.

For ease of explanation herein, the cushioning material 14 will generally be referred to as a roving material 14. The roving material 14 can comprise texturized or bulked strands or yarn roving materials made of substantially continuous strands of fibers or filaments of fiberglass material, but it is to be understood that the method and apparatus may be used with other continuous strands of fibrous material. In certain embodiments, the roving material 14 comprises one or more continuous strands of yarn materials and allows a precise positioning of the continuous strand material onto the substrate 12. In certain embodiments, the roving material 14 can have a width, W, that is between about 3 mm and 10 mm, after the roving material is wound around the substrate 12.

In certain embodiments, the roving material 14 is unwound from a package 13 and onto the substrate 12, as further explained below. One method and apparatus from which the roving material can be dispensed is shown in the Owens Corning U.S. Pat. No. 6,370,747 B1 to Lewin et al. The roving material 14 can comprise one more strands each comprising a plurality of glass filaments or fibers. Preferably, the continuous strand material comprises an OC® Bulky Rovings which are lofted rovings in a disoriented, continuous filament structure sold by Owens Coming. In other embodiments, a Type 30® strand of fibers, also made by Owens Coming can be used. Whether the strand is a roving or not, it can optionally be bulked up to provide a better cushioning effect when wound around the substrate 12. It is also within the contemplated scope of the present invention that more than one roving material can be wound onto the substrate.

The wrapping of the roving material 14 around the substrate 12 provides advantages over the prior use of mat or mesh materials. The wrapping of the roving material 14 on the substrate 12 eliminates the need to manufacture precisely shaped mats and/or mesh material which then had to be carefully affixed onto the substrate, and then inserted into a desired container, such as for example, a catalytic converter cannister or a muffler shell.

Another advantage achieved by the wrapping of the roving material 14 around the substrate 12 is that the lofty or bulky roving material 14 provides a cushioning of the substrate 12. This cushioning provides a special advantage when making catalytic converters which are both expensive and fragile, and consequently require time-consuming and expensive steps to manufacture. The cushioning provided by the roving materials also protects the catalytic converter substrate for subsequent packaging and shipping of the catalytic converter from the manufacturer to the customer.

The use of the roving material 14 provides an additional manufacturing advantage since the roving material is “pre-manufactured” and is a ready-to-use material. In addition, the process of wrapping the roving material 14 around the substrate 12 itself is less costly and is easier to use than prior processes. Also, the use of the roving material allows for more flexibility in manufacturing different types of end products, such as different sized and shaped catalytic converters and/or muffler inserts. In other embodiments, the roving material can be texturized inline before it is wound around the substrate.

Another advantage is achieved when wrapping the roving material 14 around a substrate 12 that is to be longitudinally inserted into a container, such as, for example a cannister 61 as shown in FIG. 2. The desired tension of the roving material 14 can be adjusted as the roving material is wound on the substrate 12. The control of the tension, or tightness, of the roving material 14 at its placement relative to the substrate 12 avoids the problem of any sliding of the material from the substrate, and prevents winding the roving material 14 under so much tension that the substrate 12 is crushed or otherwise damaged. In the past, the mat and/or mesh material often slid off or was skewed relative to the substrate during the insertion of the mat and/or mesh covered substrate into its container.

Another advantage is provided by the loft, or density, characteristics of the roving material 14 itself. Often, the substrate and the container in which it is held have different coefficients of linear or thermal expansion. As shown in FIG. 2, the wrapped roving material 14 fills a gap 68 that exists between the substrate 12 and its container 61. The wrapped roving material 14 provides sufficient internal pressure to maintain the wrapped substrate 12 in position in the container 61. The roving-filled gap 68 compensates for the variations in the coefficients of linear or thermal expansion which occur during the successive heat cycles that substrates such as catalytic converters and mufflers must endure. The gap 68 is sufficiently filled so that the wrapped substrate is not loose within the cannister 61 and does not bump against the sides of the cannister 61. This cushioning of the wrapped roving material provides a special advantage in catalytic converters since the catalytic converter substrate 12 is fragile and easily damaged. Moreover, the differentials in linear thermal expansion between substrate & canister (and consequently the variation in gap size) are handled by the relative consistency of internal pressure created by the wound cushioning material.

Referring now to FIG. 1, a schematic illustration of one suitable apparatus 10 for wrapping the roving material 14 around the substrate 12 is shown. The apparatus 10 includes a drive plate 20 spaced apart from a press plate 30, and a strand guide 40. The substrate 12 is temporarily mounted between the drive plate 20 and the press plate 30 for receiving the roving material 14, as further explained below.

The substrate 12 has a first end 16 and an opposing second end 18. The first end 16 of the substrate is engaged by the drive plate 20, and the second end 18 of the substrate 12 is spaced apart from the drive plate 20 in the direction along the longitudinal axis A.

The press plate 30 is axially movable along the axis A in a direction toward the second end 18 of the substrate 12. In certain embodiments, the press plate 30 can be freely rotatable about the longitudinal axis A.

The press plate 30 is slideably brought into engaging contact with the second end 18 so that the substrate 12 is snugly held in position between the drive plate 20 and the press plate 30. The press plate 30 includes a holding member 34 which keeps the press plate 30 engaged with the second end 18 of the substrate 12 as the substrate 14 is rotated about the axis A by the drive plate 20. The holding member 34 can be any suitable device which supplies a constant and securing force against the second end 18 of the substrate 12 so that the substrate 12 does not wobble or become unbalanced during the winding of the roving material 14.

The drive plate 20 is driven by a motor 22 which rotates the drive plate 20 about a longitudinal axis A. In certain embodiments, the motor 22 is controlled in a suitable manner so that, as the substrate 12 is covered by the roving material 14, the drive plate 20 is progressively reduced in speed to take into account the increase in diameter of the combined substrate and wound roving material as more layers of roving material are wound around the substrate. Thus, the roving material 14 is dispensed onto the substrate 12 at a substantially uniform linear rate. It is to be understood that, in certain embodiments, the roving material could also be dispensed at a non-uniform rate; for example, the non-uniform dispensing of the roving material would prevent any slack in the roving material when non-cylindrical substrates are being wound with the roving material.

The strand guide 40 is mounted in a parallel relationship to the longitudinal axis A. The strand guide 40 directs the roving material 14 so that it can be wound around the rotating substrate 12. It is to be understood that various types of strand guides 40 can be used to dispense the roving material 14 onto the substrate 12. In certain embodiments, the strand guide 40 can include a linearly reciprocating dispensing member 42 which traverses along a desired length of the substrate 12. It is to be understood that other means may be employed for reciprocating or traversing the dispensing member 42.

The strand guide 40 is configured to control the tension of the roving material 14 as it is being wound around the substrate 12. The winding operation continues until a desired number of layers of the roving material 14 are wound around the substrate 12 to substantially ensure a homogeneous pressure distribution on the substrate 12 in order to avoid damaging or crushing the substrate 12.

The dispensing member 42 can include an eyelet 46 to prevent the roving material 14 from moving, or sliding, along the axis B. The dispensing member 42 distributes the roving material 14 lengthwise along the rotating substrate 12 in the form of successive adjacent wraps 44 of the roving material 14. The edge of each successive wrap 44 is incrementally spaced axially along the axis A at a desired spacing.

In certain embodiments, the incremental spacing of successive wraps 44 is approximately equal to a width W of the roving material 14 so that the successive wraps 44 continuously contact each other as they are coiled around the substrate 12. In certain embodiments, the roving material 14 can be applied in a non-overlapping pattern along the longitudinal length of the substrate 12. Also, in certain embodiments, the roving material 14 is wound around the substrate 12 at an angle less than about 5° from a line normal to the longitudinal axis A.

In other embodiments, more than one strand of roving material 14 can be simultaneously wound around the substrate 12. This embodiment is especially useful in order to decrease the manufacturing cycle times and/or to wrap substrates that have a large diameter or perimeter. In such embodiment, the wrap 44 comprises more than one strand of the roving material 14. The incremental spacing the multiple-strand wraps 44 is approximately equal to a width of the multiple-strand wrap 44 so that the successive multiple-strand wraps 44 continuously contact each other, as they are coiled around the substrate 12. The roving material 14 can be applied in a non-overlapping pattern along the longitudinal length of the substrate 12. Also, in such embodiments, the winding angle as the multiple-strand wrap 44 is wound around the substrate 12 is preferably kept at an angle less than about 5° from a line normal to the longitudinal axis A. In certain embodiments, if the roving material 14 is applied to the substrate 12 at an angle that too great, the wrap of roving material has a somewhat elliptical shape and the roving material can be too loose and/or slide off the substrate.

A suitable filament winding process is used to position a first end of the roving material near the substrate in order to begin the winding step. To begin the winding operation, a first end (not shown) of the roving material 14 is guided through the strand guide 40. The first end of the roving material is at least temporarily secured to the substrate in a suitable manner. In certain embodiments, the first end of the roving material is wound a first turn on the substrate at a mid section of the substrate length so that the first, fixed end of the roving material is hidden by further winding layers and is locked by such subsequent winding layers. By beginning at a midsection only one loose tail or end is present. Also, care is taken to ensure that no knot or other unevenness is present in order to prevent or minimize uneven pressure from being exerted by subsequent wraps on the substrate. Similarly, while not shown, at the end of the windings, a tail end of the roving material can be suitably secured to the wound roving layer. Other means can be used to secure the ends of the roving material 40 to the substrate 12.

In operation, the motor 22 is energized to rotate the drive plate 20 to wind the roving material 14 around the substrate 12. The strand guide 40 is activated to reciprocate the dispensing member 42 along an axis B that is substantially parallel to the longitudinal axis A. The dispensing member 42 thus traverses along a desired length of the substrate 12 such that the roving material 14 is dispensed around the outer circumference of the substrate 12.

In another embodiment, the substrate 12 can be reciprocally moved along the axis A, and the strand guide 40 can be held substantially stationary.

Also, in certain embodiments, the drive plate 20 includes a resilient engaging surface 26 which is in contact with the first end 16 of the substrate 12. The engaging surface 26 provides a gripping surface to aid in holding the first end 16 of the substrate 12 in a secure position within the apparatus 10 without damaging the first end 16 of the substrate 12 as the substrate 12 is being rotated.

Also, in certain embodiments, the press plate 30 includes a resilient engaging surface 28 which is in contact with the second end 18 of the substrate 12. The engaging surface 28 provides a gripping surface to aid in holding the second end 18 of the substrate 12 in a secure position within the apparatus 10 without damaging the second end 18 of the substrate 12 as the substrate 12 is being rotated.

Optionally, the resilient engaging surfaces 26, 28 are each in contact with substantially the entire planar surface of the end surfaces 16, 18, respectively, of the substrate 12. The resilient engaging surfaces 26, 28 distribute the axial pressures being applied to the rotating substrate 12 over substantially the entire ends 16, 18 to minimize or prevent damage or crushing of the ends 16, 18.

Referring again to FIG. 1, the apparatus 10 can further optionally include a localization element 50 which is positioned against one or more of the first and/or second ends 16, 18 of the substrate 12. The localization element 50 helps in proper positioning of the substrate, and is configured to minimize or substantially prevent vibrations of the substrate 12 during the rotation of the substrate 12.

Referring now to FIG. 2, a catalytic converter assembly 60 having a catalytic converter insert 12 c is schematically illustrated. The catalytic converter insert 12 c comprises a catalytic converter substrate 12 wrapped with the roving material 14 according to the method of the present invention. The catalytic converter assembly 60 includes a catalytic converter canister 61 such as an outer shell which defines an opening 62. The outer shell 61 may be formed from one or more layers of a metal or metal alloy material, although it will be appreciated that any suitable material may be used to form the outer shell 61. The outer shell 61 can be formed using any suitable forming process, and can be formed having any suitable shape and dimensions. In a preferred embodiment, the outer shell 61 is generally formed having an elongated cylindrical shape that is open on each end 63, 64. The catalytic converter assembly 60 contains at least one suitable catalytic converter insert 12 c within the outer shell 61, although it will be appreciated that more than one suitable catalytic converter insert 12 c can be inserted. To complete this type of catalytic converter assembly 60, opposing end caps 66, 67 are fastened to the respective open ends 63, 64 of the outer shell 61 using any suitable mechanical fastening means, such as welding, crimping, or fastening mechanisms.

Referring now to FIG. 3, an elliptical muffler 70 design often referred to as a clamshell muffler, having a muffler insert 12 m is schematically illustrated. The muffler insert 12 m is wrapped with the roving material 14 according to the method of the present invention. The clamshell muffler 70 is generally comprised of a lower outer shell 71 and an upper outer shell 72 which define an internal cavity 74. In certain embodiments, the muffler 70 includes an optionally perforated outer an inner envelope 76 and one or more internal baffles 78. Generally, the lower outer shell 71 and upper outer shell 72 are formed from one or more layers of metal or metal alloy material, although it will be appreciated that any suitable material may be used for the lower outer shell 71 and upper outer shell 72. The lower outer shell 71 and upper outer shell 72 can be formed using any suitable forming process, such as hydroforming or stamping, and can be formed having any suitable shape and dimensions. In a preferred embodiment, the lower outer shell 71 and the upper outer shell 72 are generally formed such that the completed muffler assembly is elongated and has an elliptical cross-sectional shape, with each portion of the shell shaped as one half of the ellipse divided symmetrically about the major axis of the completed muffler assembly.

While the invention has been described with reference to a preferred embodiment, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the essential scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. 

1. A process for applying a cushioning material around a substrate that is a catalytic converter or a muffler, the process comprising: rotating the substrate, and winding one or more continuous strands of fibers around an outer surface of the rotating substrate.
 2. The process of claim 1, wherein the strand comprises a bulked up roving material.
 3. The process of claim 2, including winding the cushioning material onto the rotating substrate in successive wraps that are spaced at incremental axial distances, wherein the incremental distances are approximately equal to a width of one wrap of the cushioning material so that successive wraps continuously contact each other.
 4. The process of claim 2, wherein the cushioning material is wound around the substrate at an angle less than about 50 from a line normal to the longitudinal axis.
 5. The process of claim 3, wherein the wrap comprises more than one strand substantially simultaneously wound around the substrate.
 6. A process for winding a cushioning material around a substrate comprising: providing an elongated substrate having a longitudinal axis and opposing first and second ends; positioning the first end of the substrate against a drive plate, the drive plate being configured to rotate the substrate about the longitudinal axis; positioning a press plate against the second end of the substrate, and applying with the press plate a pressure sufficient to substantially hold the substrate against the drive plate; rotating the drive plate such that the substrate and press plate rotate about the longitudinal axis; and, winding the cushioning material around the rotating substrate.
 7. The process of claim 6, wherein the cushioning material comprises one or more strands of fibers.
 8. The process of claim 7, wherein the strand comprises a bulked up roving material.
 9. The process of claim 8, wherein the cushioning material is wound around the substrate at an angle less than about 5 ° from a line normal to the longitudinal axis.
 10. The process of claim 6, including winding the cushioning material onto the rotating substrate in successive wraps that are spaced at incremental axial distances, wherein the incremental distances are approximately equal to a width of one wrap of the cushioning material so that successive wraps continuously contact each other.
 11. The process of claim 7, wherein the wrap comprises more than one strand substantially simultaneously wound around the substrate.
 12. The process of claim 6, wherein the drive plate and the press plate each include a resilient surface configured to engage the ends of the substrate.
 13. The process of claim 6, wherein the substrate comprises a catalytic converter substrate or a muffler insert.
 14. A process for forming a catalytic converter comprising: providing a catalytic converter substrate; winding one or more continuous strands of fibers around the catalytic converter substrate to form an insert; and, positioning the insert within a catalytic converter cannister.
 15. The process of claim 14, wherein the substrate has a longitudinal axis, and wherein the winding step includes rotating the substrate about its longitudinal axis.
 16. The process of claim 15, wherein the strand comprises a bulked up roving material.
 17. The process of claim 16, wherein the cushioning material is wound around the substrate at an angle less than about 5° from a line normal to the longitudinal axis.
 18. An insert for a catalytic converter comprising a catalytic converter substrate having a strand of fibers wound around an outer surface of the catalytic converter substrate.
 19. The insert of claim 16, wherein the strand is a bulked up roving material wound on the substrate in successive wraps that are spaced at incremental axial distances, wherein the incremental distances are approximately equal to a width of one wrap of the roving material so that successive wraps continuously contact each other.
 20. The process of claim 19, wherein the wrap comprises more than one strand substantially simultaneously wound around the substrate.
 21. A muffler comprising a muffler insert having a strand of fibers wound around an outer surface of the muffler insert.
 22. The muffler of claim 21, wherein the strand is a bulked up roving material wound on the substrate in successive wraps that are spaced at incremental axial distances, wherein the incremental distances are approximately equal to a width of one wrap of the roving material so that successive wraps continuously contact each other. 